A group of endangered birds were released into the Paradise Marsh in National City Thursday.
The eight zoologically-bred, light-footed clapper rails were released into the local wetlands by Team Clapper Rail, a recovery program partnership between SeaWorld, the San Diego Zoo Global and Safari Park.
According to SeaWorld, these highly-endangered marsh birds are the second release of the breeding season.
The bird was once abundant in California wetlands but since 90 percent of coastal wetlands have been altered, the natural habitat is no longer available for clapper rails, SeaWorld explained in a media release Thursday.
Clapper rails rely on healthy marsh plants such as cordgrass and pickleweed for breeding and feeding.
Clapper rails were on the brink of extinction in 1980 but recent wetland restoration projects and zoological breeding efforts have helped reintroduce the birds to the San Diego Bay area.
Since 2010, Team Clapper Rail has bred and released more than 300 clapper rails, SeaWorld said. The introduction of these zoologically-bred birds will help increase and diversify the small population in the South Bay.
Thanks to continued breeding efforts, SeaWorld said the clapper rail population has grown significantly since the 1980s, from 142 pairs in 1985 to at least 500 today.
The clapper rail recovery program is also assisted by the U.S. Fish & Wildlife Service, the U.S. Navy, the United Port of San Diego, the California Department of Fish and Game and independent wildlife biologists.